Magnetic resonance imaging, or MRI, has gained widespread utility for diagnosis as related to the various movable joints of the body, including as examples, the knee, cervical spine and the shoulder. In most instances magnetic resonance images of the movable joints are made using standard multi-slice pulse sequences. The joint of interest to a particular MRI study is immobilized in a single position, with the various cross-sectional views taken of the joint in one position.
However, important functional information regarding a joint is contained in the "operation" of the joint when it moves through its natural range of motion. In order to make the kinematic study of movable joints practical and of clinical utility, fixtures which interface between the movable joints of a patient and the magnetic resonance imaging apparatus are necessary.
Such fixtures should incorporate a number of important features. For example, fixtures should enable a sufficient range of motion of the joint to provide a complete view of joint functionality. In addition, the fixtures should provide for numerous incremental joint positions over the range of motion, with precise control, to enable a kinematic representation of the joint motion. Furthermore, the movement of the joint among the different positions, and the acquisition of magnetic resonance imaging data at each of these positions should be automated to enhance the practical implementation of multipositional joint imaging. Finally, to provide a high level of clinical utility, the fixtures should accommodate most of the major movable joints of the body.
At the present time only limited studies have been conducted with respect to some of the movable joints of the body, but all these studies are limited by a lack of apparatuses and methods which make the capability of kinematic study of movable joints of the body a common feature of magnetic resonance imaging apparatuses. Thus useful diagnostic information obtained in a standard clinical setting has not been achieved.
Current techniques for kinematic joint studies are generally characterized by a small number of positions of the joint; a small range of motion of the joint; manual operation of the apparatus in a cumbersome fashion; and failure to address comprehensively the various joints of the body, and the different directions of motion any given joint may be capable of.
The object of the invention described herein is to provide a new and useful dimension to the clinical utility of magnetic resonance imaging as related to multipositional studies of the movable joints of the body.